use threads;
use threads::shared;

my @output : shared;

$output[0] = "irrelevant1";
$output[0][0] = "irrelevant2";

$thr = threads->new(\&test);
$thr->join;

print "-> ".$output[1]."\n";
print "-> ".$output[1][0]."\n";

print " Wo ist mein WHATTHEFUCK???? :( \n\n";

sub test {
 $output[1] = "Works!";
 $output[1][0] = "WHATTHEFUCK??";
}